title: The timing of binding and segregation of two compound aftereffects.
abstract: Temporal information in a scene is thought to be an important cue for visual grouping of local image features into a single object. The majority of studies on this topic have attempted to determine the conditions that facilitate segregation of a figure from a cluttered background. Here we examine the temporal characteristics of two aftereffects that appear to have roles in visual integration: the curvature aftereffect (CAE; Hancock & Peirce, 2008) and plaid-selective contrast adaptation (Peirce & Taylor, 2006). Both aftereffects used a "compound adaptation" paradigm measuring adaptation to a compound stimulus that cannot be explained by adaptation to its components presented in isolation. The temporal tuning characteristics of the two aftereffects differed in three distinct ways. First, plaid-selective adaptation was very sensitive to temporal phase asynchronies, while the CAE was not. Second, while both aftereffects showed integration of alternating components above 4 Hz, for plaids the overall magnitude of adaptation was less than to synchronous stimuli and was eliminated at the highest frequencies. Finally, plaid-selective adaptation demonstrated a low-pass dependency for temporal flicker frequency of synchronous gratings, whereas the CAE did not. Overall, these results suggest that at least two different mechanisms are involved in the binding/segregation of local signals into compound patterns: one with high temporal resolution that allows rapid parsing of plaid patterns into their components and one with a coarser temporal sensitivity that mediates the CAE.
authors.affiliation: Nottingham Visual Neuroscience, School of Psychology, University of Nottingham, Nottingham, UK.
authors.forename: David P
authors.initials: DP
authors.lastname: McGovern
authors.forename: Sarah
authors.initials: S
authors.lastname: Hancock
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Peirce
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology*; D015350:Contrast Sensitivity; D005366:Figural Aftereffect / Q000502:physiology*; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011594:Psychometrics; D012684:Sensory Thresholds